I don’t even think there’s dirt in there. It’s an old birdbath with the top removed.
Fun fact, the vast majority of the mass of a plant is extracted from the CO2 in the air, not from matter in the ground.
Trees mainly appear out of thin air
And conversely, when we lose weight the vast majority is exhaled as CO2, not excreted as liquid or solid waste.
Does it technically even need dirt? It looks like there’s some loose debris in there and plenty of plants can be grown hydroponically.
No but that’s part of my point. It’s the fact that all that’s in this thing is debris and yet something is alive and growing.
Life truly does find a way.
My nephew has moss growing out of his bike saddle.
Looks like there’s mulch in there. Plants can grow in mulch, especially as it breaks down into soil.
It sits under a tree so that would be the only way any noticeable amount of organic material would be collected.
I sometimes forget that dirt is just decayed plant/animal matter compacted and built up over time.
The stuff trees drop during the year (and then many homeowners take away) is the tree desperately trying to create its own shoes
